This invention relates to an apparatus for carrying out an examination on the breast, in particular for carrying out mammography and/or tomosynthesis (“digital breast tomosynthesis”, DBT), and biopsy.
There are known apparatuses for mammography/tomosynthesis that comprise a source configured to emit X-rays and a detector configured to receive the X-rays emitted by the source.
It should be noted that the patient's breast being analyzed is interposed between the X-ray source and the detector in such a way that the X-rays pass through it.
These apparatuses can also be easily equipped with a system for stereotaxic biopsy. This system consists of a method for the computation of the exact position of a region of interest inside the breast, by means of the acquisition of a number of images at predetermined angles with respect to a rotation fulcrum, and of a probe (motor-driven or not) for extraction of tissue by incision.
The two main approaches for stereotaxic biopsy are in the prone position and the vertical position.
An apparatus for mammography and tomosynthesis generally allows a stereotaxic biopsy to be carried out with the patient positioned with the trunk vertical, standing or seated.
A biopsy performed in the vertical position makes it possible to reduce the time of the procedure, and makes the procedure easier if the patient has small breasts.
It is, however, preferable to also have the possibility of performing the biopsy in the prone position (with the patient lying on a dedicated table above the system), since in most cases this method increases patient comfort, reducing the risk of movement and extending accessibility to the breast. The prone table allows two people to work comfortably around the patient, making the procedure more efficient. It has also been demonstrated that vasovagal reactions (fainting) occur less frequently in the prone position.
Prone biopsy systems are generally available on dedicated apparatuses, which therefore require additional space and expense with respect to vertical mammography systems and which thus cannot be accommodated in all health settings.
The patent document EP0387475 describes an apparatus able to perform mammography and stereotaxic biopsy both in vertical position and in prone position, but this apparatus is not able to perform tomosynthesis or other types of breast examination. Moreover, in the above apparatus the movement from the vertical position to the prone position is achieved in such a way that the dimensions of the machine sometimes hinder the performance of the prone biopsy.
A further requirement is thus the availability of an apparatus with a structure that is not too bulky for it to be used in not particularly spacious settings.
The patent document U.S. Pat. No. 5,305,365 describes an example of a machine for mammography that can perform a partial rotation of the analysis head, for a very limited angle, to favor the performance of the mammography on the patient.
This machine comprises a load-bearing frame that supports a mobile analysis head between a vertical position, in which the patient undergoes analyses while standing, and an inclined position, in which the patient undergoes analyses with the chest in a vertical position. Although this system has limited dimensions, its purpose does not correspond to the requirement expressed above that is to say of providing an apparatus of simple design which allows the medical staff to perform examinations on the patients breast in the erect and prone positions.
Nuclear medicine is distinguished from radiology by the fact that it does not have a radioactive source outside the patient (transmission imaging), but the patient him/herself becomes the source of radiation (emission imaging) by administration of a radioactive drug, and it is not therefore a measure of radiation attenuation that passes through the body, but a measure of distribution and intensity of the radiation emitted by the body. The analysis head for a nuclear medicine application requires one or more gamma ray detectors, coupled to a collimation system (physical or electronic by means of coincidence detection) which makes it possible to select and identify the source direction of the photon.
As already indicated for biopsy examinations, nuclear medicine tests can also favor the prone or erect position depending on the duration of the test and the specific application. The possibility of using an apparatus in both positions, not limited to radiological applications, thus makes the invention even more useful.
An additional advantage is that tomosynthesis can be performed in the prone position, so that the image obtained can be used as a guide for the subsequent biopsy sample.
This invention also intends to provide a particularly versatile apparatus that can be used to perform a plurality of examinations on the breast.
With a different analysis head in addition to or replacing the combination between X-ray source and X-ray detector, the same mechanical structure can be used for other types of breast examinations, such as for example (but not only) nuclear medicine examinations.